Local excision vs. proctectomy in patients with ypT0-1 rectal cancer following neoadjuvant therapy: a propensity...

We aimed to evaluate outcomes of organ preservation by local excision (LE) compared to proctectomy following neoadjuvant therapy for rectal cancer.

This retrospective observational study using the National Cancer Database (NCDB) included patients with locally advanced non-metastatic rectal cancer (ypT0-1 tumors) treated with neoadjuvant therapy between 2004 and 2019. Outcomes of patients who underwent LE or proctectomy were compared. 1:1 propensity score matching including patient demographics, clinical and therapeutic factors was used to minimize selection bias. Main outcome was overall survival (OS).

11,256 of 318,548 patients were included, 526 (4.6%) of whom underwent LE. After matching, mean 5-year OS was similar between the groups (54.1 vs. 54.2 months; p = 0.881). Positive resection margins (1.2% vs. 0.6%; p = 0.45), pathologic T stage (p = 0.07), 30-day mortality (0.6% vs. 0.6%; p = 1), and 90-day mortality (1.5% vs. 1.2%; p = 0.75) were comparable between the groups. Length of stay (1 vs. 6 days; p < 0.001) and 30-day readmission rate (5.3% vs. 10.3%; p = 0.02) were lower in LE patients. Multivariate analysis of predictors of OS demonstrated male sex (HR 1.38, 95% CI 1.08-1.77; p = 0.009), higher Charlson score (HR 1.52, 95% CI 1.29-1.79; p < 0.001), poorly differentiated carcinoma (HR 1.61, 95% CI 1.08-2.39; p = 0.02), mucinous carcinoma (HR 3.53, 95% CI 1.72-7.24; p < 0.001), and pathological T1 (HR 1.45, 95% CI 1.14-1.84; p = 0.002) were independent predictors of increased mortality. LE did not correlate with worse OS (HR 0.91, 95% CI 0.42-1.97; p = 0.82).

Our findings show no overall significant survival difference between LE and total mesorectal excision, including ypT1 tumors. Moreover, patients with poorly differentiated or mucinous adenocarcinomas generally had poorer outcomes, regardless of surgical method.